Right, thanks for the explanation on why the tensor exists. That single paragraph was far more intuitive that anything I've read so far!
Regarding the CoG, is this going to work? If I have a box lying on the ground with it's CoG a lot below the ground, and apply a torque to it, it wants to rock on the ground but according to the pendulum action it would have from the CoG, not from the ground.
Bascially, the centre of mass needs to be set at an arbitrary point outside of its "visible mass". It's not so much the graphics, but the position relative to the bounding object. The tensor seems to be the only way to add this extra parameter but I can't work out how.
And I really don't get how I seem to be the only guy thinking this is a bit odd so I hope I'm missing something. Couldn't find anything online. Am assuming my question has the same effect it does when a layman asks a mathematician anything - that look on their face as if you just shit in their mouth. Or is that just the two experts I used to know?!